I apologize for bumping this old topic, but I have done quite a bit of research on this, so I want to share my experience.
I thought I'd throw a few more cents into the discussion.

IMHO, a play kitchen can be enjoyed anytime from 18 months on - but of course, as with all things, it will be different things to your child at different ages.

We didn't have a play kitchen by Ikea or Kidkraft https://toyboxadvisor.com/best-wooden-play-kitchens for DD at 18 months but she liked to play with the one on display at Target, plus another one at a playgroup. At that age, it was all about opening the doors, placing an object inside, closing the door, opening again, etc. Now DD is 25 months and we just got her a kitchen, and now she clearly understands the "pretend" part - that it's a kitchen like the one where Mama and Daddy cook and wash dishes. She still loves to open and shut the doors now, but it's different already. But right now she's not too specific about her motions in pretending to do things - for example, we have a wooden "macaroni and cheese" box and a play pot - she doesn't know yet how to "pretend" to pour the macaroni in the pot and stir it around and then serve it in a bowl. That will come later.
On YouTube there are a lot of interesting videos on this topic, I will share with you, one of them, hope this will help someone. Good luckhttps://www.youtube.com/watch?v=oUk008Daius